1. Technical Field
The invention relates to a plug flow reactor. The invention particularly relates to a plug flow reactor for use in preparing polystyrene and impact polystyrene.
2. Background of the Art
Exothermic processes for the production of compositions such as, for example, polystyrene are known. In these processes, the reactants are first heated to initiate the reaction, but then the reactants are cooled during the reaction. The capacity to cool the reactants is often a limiting process parameter.
Such highly exothermic processes, unless carefully controlled, can cause the operation of reactors both to be hazardous and to lead to undesirable side reactions. For example, in the production of synthetic natural gas, run-away reactor conditions can lead to the depositing of coke and eventually plugging the equipment. Control of such reactors can be further complicated as a commercial reactors generally must handle reactant feeds that may vary widely in composition over a given period of time.
One solution to this problem is to use a back-mixed reactor. In such a reactor there ideally is no temperature gradient as the material within the reactor is of uniform composition and temperature. There are several means of achieving a back-mixed reactor which means are well known to those versed in the art. These include the use of a fluidized bed of solid material as well as back-mixing by purely hydrodynamic means. While the back-mixed reactor is a satisfactory manner of solving the problem of temperature control, it has several disadvantages when compared to a plug-flow reactor. Many applications require reaction conditions having minimal back-mixing such as that found in a plugflow reactor. Also, use of a back-mixed reactor may lead to problems in the formation of unwanted by-products.
Thus, it would be desirable in the art to prepare certain products using a plug flow reactor that has good temperature control and is economical to employ.